/*
 * Copyright 2018 Youchaoshi authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package common.tool;

import java.security.MessageDigest;

/**
 * MD5加密解密
 */
public class MD5Util {  
  
    /*** 
     * MD5加码 生成32位小写md5码
     */  
    public static String string2MD5(String inStr){

        MessageDigest md5 = null;
        try{  
            md5 = MessageDigest.getInstance("MD5");
        }catch (Exception e){
            System.out.println(e.toString());
            e.printStackTrace();  
            return "";  
        }  
        char[] charArray = inStr.toCharArray();
        byte[] byteArray = new byte[charArray.length];  
  
        for (int i = 0; i < charArray.length; i++)  
            byteArray[i] = (byte) charArray[i];  
        byte[] md5Bytes = md5.digest(byteArray);  
        StringBuffer hexValue = new StringBuffer();
        for (int i = 0; i < md5Bytes.length; i++){  
            int val = ((int) md5Bytes[i]) & 0xff;  
            if (val < 16)  
                hexValue.append("0");  
            hexValue.append(Integer.toHexString(val));
        }  
        return hexValue.toString();  
  
    }  
  
    /** 
     * 加密解密算法 执行一次加密，两次解密 
     */   
    public static String convertMD5(String inStr){
  
        char[] a = inStr.toCharArray();  
        for (int i = 0; i < a.length; i++){  
            a[i] = (char) (a[i] ^ 't');  
        }  
        String s = new String(a);
        return s;  
  
    }  
  
//    // 测试主函数  
//    public static void main(String args[]) {  
//        String s = new String("tangfuqiang");  
//        System.out.println("原始：" + s);  
//        System.out.println("MD5后：" + string2MD5(s));  
//        System.out.println("加密的：" + convertMD5(s));  
//        System.out.println("解密的：" + convertMD5(convertMD5(s)));  
//  
//    }  
} 